Gear-roughing machine



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J. EDGAR GEAR ROUGHING MACHINE Sept. 6, 1927.

Fled Feb. 2 1924 9 Sheets-Sheet 9 22 15 99 Patented Sept. 6, 1927.

UNITED STATES- 1,641,666 PATENT OFFICE.

JOHN EDGAR, OF B OCKFORD, ILLINOIS, ASSIGNOR 'IO BARBEIt-COLMAN COMPANY, OF ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS.

GEAR-:ROUGHING MACHINE.

' ture of worm wheels, on the other hand, the

hob, having its axis disposed at right angles to the axis of the gear blank, is moved radially into engagement with the periphery of the blank. In this instance, the time consumed in the cutting operation is substan- ,tii1lly less than in the case of the feed employed in the manufacture of spur gears.

Because of the relative rapidity with which teeth may be formed by the radial feed method, I utilize this method in roughing spur gear blanks, and in order-to reduce to a practical minimum the concavity of the peripheral surface of the partially com-v pleted gear I employ a hob of large diamblank.

The primary object of my invention is to produce a machine for performing the pre liminary roughing operation above referred to, which 'is of a practical character, and which employs the radial feed method so as to render it possible to,perforii the roughing operation at relatively high speed- A further object is to produce a machine I in which it is possible to operate upon two blanks fed into engagement with opposite sides of the rotating cutter, thus'further in creasing the capacity of the machine.

Another object is to provide a machine which is constructed to permit of easy ad-' justment for the purpose of operating upon gear blanks of various sizes.

Still another object is to provide novel means for moving the work into andjout of engagement with thecutter, and means associated with the feeding means for rotating the work.

Still another object is to provide a ma chine of the character indicated in which either one or two blanks may be operated eter as compared to the thickness'of the gear I upon at the will of the operator, and in which means is iovided for automatically stopping the wor holders upon the completion of-the roughing operation to permit the removal of the work and the insertion of new blanks for the next operation.

In the accompanyin drawings, wherein I have illustrated a pre erred embodiment of my invention: J

-. Figure 1 is a plan view of the machine. n Fig. 2 is a front elevational View. Fig. 3 is a rear side view. Figs. 4 and 5 are end views looking from the right and left hand ends, respectively,

of the machine, as shown in-Fig. l.

Fig. 6 is a fragmentary vertical .sectional view taken substantially in the plane of line 6-6 of Fig. 4 on an enlarged scale.

Fig. 7 is a fragmentary vertical sectional view taken in the plane of line 7-7 of Fig. 2, also upon an enlarged scale.

Fig. 8 is a fragmentary vertical sectional view on an enlarged scale of the means shown in Fig. 6 for driving the work-hold ing spindle.

Fig. 9 is a fragmentary underside view il lustrating a means for adjusting a worm wheel spindle.

.Fig. 10 is a horizontal sectional view through the machine, illustrating the driving mechanism for the various movable parts.

Fig. 11 is a view illustrating the development of one of the feed cams and showing the sequence of operations.

Fig. 12 is a fragmentary vertical sectional view taken substantially in the plane of line 1212 of Fig; 2 and showing one of the work-holding fixtures. i

Fig. 13 isa fragmentary vertical sectional view illustrating the relative positions of the cutter and the work at the end of the feeding movement.

Figs. 14, 15 and 16 are diagrammatic views illustrating the operation of roughing a gear blank.

Fig. 17 is a fragmentary vertical sectional view taken in the plane of line 17-17 of 1 Fig. 2, the work-holding fixture being shown in section.

Fig. 18 is a view similarto Fig. 13 but showing the cutter engaging with the work von the left side of the cutter.

Fig. 19 is a view similar. to Fig; 16 but 50 constant caring connection between a driven 22.22 of Fig. 20.

showing the work'on; theopposite side of the cutter from that'shown'in Fig. 16. Figs. 20 and 21 are fragmentaryTplan views illustrating .the means for automat cally stopping the carriages which support the work-holding fixtures, and also inter-. rupting the rotation of the fixtures in inoperative positions at the completion of the roughing operations; the parts. being shown in different operative positions in the two views. I Fig. '22 is a fragmentary vertical sectional view illustrating the details of construction of the clutch-operating lever shown in Figs. 20 and 21, the view being taken on line f Fig. 23is a fra mentary rear side view of the change spec gearing for drivingone ofthefeedcams;

The machine which I have selected for purposes ofillustration may be termed a double-ended machine in that the construc-..

" tion at opposite ends is substantially duplialso are arranged to control the rotation '0f the blanlespindles comprised in'the workholding fixtures Land 4; but the hob 5 is cated so as to render it possible .to "operate upon two blanks moved into and out of en agement with the opposite "sides of the ho To support the work for such movement, I provi e t'wo longitudinally movable carriages 1 and 1 each of which is mounted for movement in ways 2 (Figs. 4 and 5) on the upper side of the elongated base3. At the inner end of the carriages 1 and 1' are provided means including work-holding fix turcs 4 and 4 respectively (Fig. for supporting the work for rotation whi e itis beingmovcd radially into and out of engagement with the hob. The latter, in the present instance, is indicated by the numeral and is mounted to turn on an axis extending transversely of the machine and midway of the length of the bed 3. A pair of cams 6 and 6' (Fig. form iprocating the'carriages 1 and 1. are mount (1 at opposite ends of the base and connected with a suitable source of power b means including clutches 7 and 7.' aid .clutchcs continuously driven by means ,pr'ovidingm shaft an hob;

Referring now to Figs. 1 and 10, 9 designates a shaft to which power isapplied as bymeans of a' pulle 10 and belt 10 under the control of aclutc '11 having a forwardly extending operating lever 11. The forward end of said shaft 9 is journalled in the present instance. in a gear housing 12 rigid with the base at the rear side thereo and said end of the. shaft is connected by bevel gearing 13 with a longitudinally'extending shaft 9. spindle 8. (Fig. 7).;" jcarrying the 14- journalled between its ends in the, housing 12 and having its extreme ends rotatably end.

1,e41,eee

end in'the housing 15 or 15', as the case miiy be. eferring now to the right hand end of the machine (Fig. 10) the forward end of the shaft 13 is journalled in a bearing 19 suitably supported on an inner upright wall 20 formed integral with the base, and the rear end of the shaft 18 is coimected by a change speed gear train 21 of suitable construction with a parallel shaft '22. The rear end of saidshaft 22 is mounted in a lateral extension of the housing 15 audits fbrward end passes through an elongatedmember 23 and 1s squared as at 22 to receive a crank for purposes of manual operation; The

shaft is supported inthe member 23 at. spaced intervals by means of bearings 24 and between two of such'bearings 24 is secured a worm 25 meshing with a worm wheel 26 (Fig. 6) rigid with the cam 6. The latter is rotatably supported in a chamber at the end of the base through the medium" of. spaced rollerbearings 27.nn a shaft 28 which shaft 28 is shown as being supported at one end in a plate 29 on the end wall 20 of the base and at its other end by a removable plate 20*"- closing the cam chamber. Preferably apaiiof rollers 29 are mounted is suitably mounted in the base. Herein the g upon the base so as to engage with opposite sides ofthe cam adjacent the point of enga ement between the cam and the carriage as hereinafter set forth.

The plate 29 (Fig. 10) has a forward ex tension to form-the member 19 which'supports the forward end of the shaft 18. Also, said plate supports one end of a shafti30 which is connected by bevel gearing 31 with the shaft 18 for rotation by the latter. 'At

. its inner end the shaft 3() has-a splin'ed connection-with a worth 32 mounted in a rearward extension 33 of a casing 34 (Fig. 6) rigidly secured to the underside of the carria e I. A shaft 35 (Fig. 8) which .normally is fixed in. position has its lower end supported in the bottoi'n of the casing 34 and its upperend supported in the carriage 1. Journalled on said shaft 35 is a sleeve or tubular shaft '37 ii id with which is a worm wheel 38 with w iich the worm 32 is arranged to mesh. "The sleeve 37, in turn, its connected by gears" 39 and 40 (Fig; 6) with the lower section of a spindle 41 constitutin a part of the work-holding -fix-' ture. is vpointed out hereinafter, the axis spindle is therefore made spiral of the same angle asthe helix angle of the hob so that it shall mesh with the spur gear 39 on the .swormwheel 38-.with respect tothe worm 32,

so as to insure that .these gears shall mesh 'properly,iI preferably support the ends of 1 the shaft upon studs" 42 and 42 (Fig.

8) which are eccentric with relation to the tubular shaft 37-, "said studs being journalled in the carriage and in the lower end of the offsaid member is arranged to clamp 1t and hold the shaft in the desired position of casing 34. To the lower end of the shaft 35 is fixed a 'slotted member 43 (Figs. 6

A bolt'44 entered through the slot adjustment.

It will be seen that the rotation of the carriage-reciprocating cam 6 and of the blank spindle 41 is under the control of the clutch 7, since the latter is interposed be-' tween the driven shaft 9 and .the shaft 18 with which the cam and the blank spindle are both connected. By a similar construction and arrangement the cam 6 and the blank spindle of the work holding fixture 4' are under the control ofthe clutch 7.

' The hob 5, however, is constantly driven by a continuous connection between its spindle 8 and the shaft 14. This connection comprises in the present instance a worm 45 (Figs. 7 and 10) fast upon a shaft 46 which is journalled at its opposite ends within an -elongated section 47 of a gear case 48 at the rear side of the machine. Said shaft 46 projects from one end of the portion 47 of the case and is connected by a gear train 49 with the shaft 14. A worm wheel 50 (Fig. 7) on the hob spindle 8 meshes with the worm 45.

The carriage 1 is connected with the cam 6 for movement thereby through the medium means of 'of a plate 51 (Fig.

6) which is secured upon the carriage as by means of screws 52 entered in slots 53 (Fig. 1) and anchored 1 in the carriage. Approximately centrally of the carriage there is pro- 'vided an aperture 54' (Fig. 6)" through which depends, a portion 55. on the plate 51 having secured upon its under side on studs 56- a pair of rollers 57 which are the upper side 0 ,spaced apart in order to receive between them the peripheral portionof the cam 6. Rigid with the plate 51 is an upstanding nut 58 with which the threaded end 59 of an adjusting screw 60 engages. Said screw is rotatable in a head 61 mounted upon the end of the carriage, but is held against longitudinal movement in said head by spaced collars 62 and 63. After loosening the nuts 52, it will-be observed. the carriage 1 may be adjusted fl'o'ngitudinally with respect to the plate 51' meansof a crank applied to the square end of the screw 60. Thus it is possible to adjust the position of the carriage in ac cordance with'blanks of various diameters.

The carriage 1' with its work-holding'fixture .is actuated by means similar in all substantial respects to that explained in con-" nection with the carriage 1, so that a description of such means is unnecessary. Also the work-holding fixtures" 4 and 4' are. sub stantially identical in construction so that a description of one will sufiice. Thefixture 4 comprises a lower section 64 (Figs. 2 and 17) rigidly secured upon the inner: end of the carriage and supported upon blocks 65 and 66 having their upper surfaces inclined so as to impart to the fixture the proper degree of inclination with respect to the angle of helix of the hob in accordance with the pitch of the gear being cut, the number of threads on the hob,'etc. In said lower section 64 of the fixture, concentrically thereof is a tubular member 67 (Fig. 17

carrying journal boxes 68 and 69 in which i is mounted the lower section 41 of the spindle'69 is a collar on the spindle 41 between the bearings 68 and 69. Thrust Washers 69 are interposed between collar 69*, and the adjacent ends of said bearings.

Upon the lower section 64 of the fixture is mounted an upper section 70 secured in position as by means of screws 71. Both of said sections are shaped to provide a guard for one side of the hob 5, a similar guard being provided by the fixture on the other side of the hob (see Fig. 2). In the reduced end of the upper section 70 is, mounted the upper section-41 of the spindle. Suitable bearings 72 and 73 support the spindle section 41 for up and down and rotary movement, its upper end being provided with a hand wheel 74. V

The two sections 41 and 41. of the spindle are arranged to clamp a gear blank (1 between them, and to this end the lower sectIOfI 41 has a screw-threaded upper extension 75 which is arranged to enter the lower internally screw-threaded end of theupper section 41. The respective sections carry clamping members 76 and 77 held against endwise movement, and the arrangement is upon the lower end of the upper section 41* below the clamping member 76. To facilitate such insertion of the Work, the fixture is constructed to provide an opening 77 (Fig. 6) in its outer side through which access giay be had to' the 'mid-portionof the spinle. I i

A lever 78 (Fig. 12) is pivotally mounted between its ends at 78 upon the upper section 70 of the fixture, and its rear end has a pivotal but sliding engagement with a collar 79 uponthe upper section 41 of the spindle. By the operation of said lever 78 the two sections of the spindle may be sepa rated, assuming, of course, that the hand openings 94 and 94% in the base (Fig; 6)- 65' wheel 7 4 has been operated to disconnect the sections at their adjoining ends. A. gear blank may then be readily placed upon the lower end of the section 41, after which the lever 7 8 may be operated to lower the spindle section 41' into engagement with the section 41, the blank being then clamped in position by operation of the hand wheel. If the work shouldstick to the upper spindle it may be removed by operating the lever 78 to carry it into engagement witha tubularflstripper member79 rigid with the stationary portion 70 of the fixture.

The hob spindle 8 (Fig. 7) is mounted on thebase within a head 80 which also carries at its rear end the housing48 that encloses the worm wheel 50 of the spindle drive mechanism. As shown in Fig. 7, the

:9 hob is bolted to a flange 81 on the spindle 8. Near the forward end of the spindle is a tapered bearing surface 82 fitting within a bearing 83 fixed in a sleeve 84. Anop-Y positely tapered bearing member 85 is '25 splined. uponthe spindle 8 andfits within a bearing 86 fixed in the sleeve 84.

A nut 87 screw-threaded upon the spindle and engaging the bearing member 85 serves to hold the bearing surface 82 and thebearing member 85 in proper running engagement with the bearings 83 and 86,

respectively, and take u wear.

The sleeve 84 is slida le within the head 80 and has, rigid therewith a block 88. pro- 3 jecting radially through an aperture 89 in the head 80 and having at'its upper end an -adj usting screw 90 engaging at one end witha lug 91 on the head'80. The screw is provided on opposite sides of the block, 88 with a pair of adjusting and locking huts 92.

By the construction provided the hob-supporting member 84 may be readily adjusted longitudinally in the head 80. As indicated in Fi s. 3 and 7, the worm wheel is l 46 connecte to the spindle 8 by means of two splines 93.

Referring now to the cams 6 and 6' for reciprocating the carriages 1 and 1,' their form is shown in Fi 11. Initially the 60 carriage is moved rapidly from the loading position to a point close to the hob. Thereupon the carriage is fed inwardly at low speed until the desired depth of cut is obtained, this being accomplished in the present instance in five revolutions of the gear blank. The feeding of the work is now suspended during one revolution thereof at the end of which the carriage is moved outwardly at a relatively high speed to an inoperative position for the purpose of unloading the completed work and loading new work upon the work s indle.

The chips produced in t e cutting o era tion are permitted to discharge throng the -on the axis 97. The arranged to ,be adju and into a removable chippan' 95 (Fig.2).

In the present-inst'anc e I have provided means for stopping the twp carriages inde pendentlyof each 'other,' /ini-.suc h inoper'a I tive positions, and also interrupting there-x; tation of the work spindles. This meanscomprises the clutches-7 and?" ar'l means'f controlled by the mo vement of the carriages to 'theirsald inoperative'bpositions to'actuate said clut hes. Y i r Thus, referring to ing Figs; 20 and 21, I have shown a for-.

. the planvviews form-" wardly extending lever 96 pivoted at its rear end at :97 in a bracket 98 secured upon the upper side of the housing 15 (Fig. 1)

Rigid with said lever is a rearwardly extending clutch-shifting yoke 99 (Fig. 22).

A forwardlyextending arm 100 is pivoted aims 96 and 100 are st blyconnected together by the following mba s. Rigid with the arm 100 is a member 10 against which ;nected by a contractile spring 107 with the lever-96. The free end of the member 102 is arranged to be engaged by a trip consisting of a screw 108 carried by a bracket 109 on the carriage.

The operation 1s as follows:

Assuming that the operator has actuated the main control clutch 11 through the medium of the hand lever 11 (Fig. 1 to start the machine in o eration, and also that one of the carriages, or example, the carriage'l, istin its inoperative position (as showniin .Fig. 21), the previously roughed gear is removed and a new blank inserted in position between the sections of the corresponding work-holding s indle. This is accomplished by operating t e hand wheel 74 to efiect 'a disconnection between the two sections of the spindle, whereupon the sections are separated b the o eration of the lever 78 to permit t e with rawal of the work'and' the nsertion of a new blank.

en the latter has been clamped in position, the control lever 96 is unlatched from the. member 102 and swung to the left to throw in'the clutch 7, the handle being swung in such operation into the. position shown in- Fig. 20. The pressure between the clutch elements serves to hold them in engagement; The cam '6 now causes the carriage 1 to ,moveinwardly and, the spring 107 beingunder tension, the

'a locking pin or detent 103 on a rod 104 1,641 see member 102 follows the trip 168 inwardly until the aperture 103 inthe member 102 a present" instance teeth are cut upofi the blank in six revolutions thereof. During the sixth revolution of the blank the carriage remains stationary so as to make the cut uniform throughout the entire periphery of the work. At the end of the sixth revolution the cam reverses the movement of the carriage and causes it to move at a relatively high speed into its initial or inoperative position. x

As the carriage approaches such initial position the trip 108 striking the member 102, now locked to the lever 96, imparts a swinging movement to the latter such as to disengage the clutch 7. The result is that the carriage comes to rest and the workholding spindle also ceases to revolve, thus permitting of the removal of the completed Work and the insertion of a blank as above described.

It will be apparent that because of the adjustment provided between the carriages 1 and l and their respective cams it is possible to operate upon blanks of different diameters, and that inasmuch as the opposite ends of the machine are subject to independent control, though actuatedby a common drive mechanism it is unnecessary that both pieces of work be operated wiipon simultaneously thus permitting the operator to attend to opposite ends of the machine successively. B the time the operator has removed a rou ed out gear, substituted a gear blank'and restarted the carriage at one end of the machine, the other carriage has completed, or nearly completed, a cycle of o erations, so that the operators time is substantially fully occupied. I

In the mounting of the work upon the carriages, as distinguished from spindles mounted in the body of the machine, I haveproduced self-contained work-holding fixtures which lend themselves to compactness in the construction of the machine.

I claim as my invention:

1. A gear roughing machine comprising, in combination, an elongated base, a hob mounted to rotate on a fixed axis extending transversely of the base, a carriage mounted for longitudinal movement upon the base at each side of said hob, a work-holding fixture on each of said carriages including a work spindle, a constantly driven shaft, a pair of cams for reciprocating said carriages toward away from the hob, means,assoc1ate d H i and with saidcams to revolve said s1pindles,l'and control--' means including a. clutc interposed between said constantly driven shaft'andeach of said cam driving means;

2. A gear roughing machine-'comprising, 1n combination, two longitudinally movable.-

carriages, apair of cams-.for reciprocating the respective carriages, a constant y driven shaft, means having a clutch controlled connection with said shaft for rotating'the respective cams, and work-holding fixtures on the respective carriages having work spindles operatively' connected (with said cam driving means. v

3. In a gear roughing machine, the. combination with a hob, a constantly driven shaft with which said hob is operatively connected, a pair of Wonk-holders, feeding means for moving said holders to .carigthe work into engagement with the hob ra ially of the latter, means for rotating the work holders during suchfeeding movement, and

means including separate clutches for the respective feeding means for controlling [the connection between said shaft and the feeding means. i

4. In a gear roughing machine, the combination of a hob mounted to rotate on a fixed axis, a carriage mounted for movement in a direction perpendicular to the axis of the hob, a work-holding fixture on the car- -riage including a spindle, a driven shaft,

a cam operatively associated with the carriage for reciprocating the carriage toward and away from the hob, means for rotating said cam including a pair of parallel shafts, and means associated with one of said shafts for rotating the spindle including means adapted to permit of the movement of the spindle with the carriage.

5. In 'a gear rough'ng machine, the com bination of a hob mounted to turn on a' fixed axis, a carriage mounted for reciprocation in a direction perpendicular to the axis of the hob, a work-holdingfixture on the carriage, and means for reciprocating the carriage including a member adjustable longitudinally with respect to the carriage, a pair of rollers on said member, and a cam engaging between said rollers.

6. In a gear roughing machine, the combination of a base, a carriage mounted to slide on said base, a hob mounted to turn on a fixed axis perpendicular to the direction of movement of the carriage, a work-holding fixture on said carriage, and means for reciprocating the carriage includin a member adjustable longitudinally thereo and cam means opera zively engaging said member.

7. In a ear roughing machine, the combination of a hob mounted to turn on a fixed axis, a work-holding fixture mounted for movement to carry the work radially .into

' engagementwith the hob, means for rotatingfi fmember, for-the carriage, and an ad ustable 1 .i i Ina I M "bin'atlomwith"a'base, a carr age mounted to -slide on said flba'se, a' -hob mounted to turn e worki'n said mo vement, an actuating connection between said member and the carg'ear roughing machine, "the comon a fixedfaxis, means including a, spindle out of engagement with the hob in the movements of the carriage, means for moving "the carriage, and means for rotating 'sald mounted .on', the "carriage and adapted to holdthe gear blank for movement into and spindle in the movement of the carriage including a worm, and a worm wheel mounted for adjustment toward-and away vfrom said worm and operatively connected with said indle.

9. n a ear roughing machine, the com- Y bination 0 a hob mounted to turn on a'fixed axis a carriage movable in a direction perpen icular to said axis, means for moving said carriage including a cam, a member on carriage.

the carriage adjustable relative thereto and operatively associated with sald cam, and means for adjusting said member on the 10. A ear roughing machine having, in

combinatmn, a hob mounted to turn on a I the return movement of the carriage to bring 1 axis, a carriage mounted for movement in .a direction pe it to rest. v, w

11. In a gear roughing machine, the combination of a hob mounted to turn on a fixed endicular to the axis of the stantly driven shaft, means connecting said shaft with said cam including a clutch, and means operable in the movement of the carriage away from the hob to actuate 'said clutch, the last-mentioned means being operable manually to cause the carriage to move toward the hob.

14. In a machine-of the scribed, the combination of a reciprocatory carriage, means for reciprocating the carriage including a clutch, alever for operating the clutch a member movable with respect to said lever, means operable asthe carriage moves in one direction for locking said member to said lever, and means operable as the carriage moves in the opposite direction to actuate said lever through said member whereby to disengage the clutch.

15. A gear roughing machine comprising,

in combination, an elongated base, a driven shaft extending longitudinally of the base,

a pair of cams mounted in the base at opp'o siteends thereof and having their axes par;

allel with said shaft, a hob spindle mounted transversely of the base substantially midway between its "ends and o eratively connected with said shaft, 3. pair of carriages mounted on the base at opposite ends thereof for movement in a direction perpendicular to the axis of the hob, means operatively connecting said cams with said carriages,

work holding fixtures mounted on the car-i riages for movement therewith and includmg work spmdles, means connecting sald spindles with said shaft adapted to permit,

of the movement of the spindles with the carriages, and means connecting saidcams with said spindle driving means.

16. A gear roughing machine comprising, in combination, an elongated base, a driven 'shaft extending longitudinally of the base,

a pair of cams mounted in the baseat oppohob, work hol ing means on the carriage, (siteends thereofand having their axes par- 1 stantly driven shaft, means connecting said riage away shaft with said cam including a clutch, and means operable in the movement of the carfrom the hob to actuate said clutch.-.

13, In a gear roughing machine, the comhination of a hobj,"a carriage aving a workholdingfixture thereon and movable to calil'ry tlieworli.*into engagement with the radially thereof including a cam, a conallel with said shaft, a hob spindle mounted transversely of the base substantially midway between its ends and operatively connected with said shaft, a pair of carriages v mounted on the base at opposite ends thereof for mo ement in a ,direction perpendicular,

to the axis of the hob, means operatively connecting said cams with said carriages, workholding fixtures mounted on the carriages for movement therewith and including work spindles, means connecting said spindleswithsaid shaft adapted to permit of the movement of the spindles with the carriages, and means associated with the opposite ends of said shaft for actuating said cams.

17. In a gear roughing machine, the combination of a base, a stationary head on the base, a hob spindle journalled in said head, a driven shaft extending longitudinally of character dethe base at the rear side thereof and operatively connected with said spindle, a car- 'riage -mounted on the base for movement in a direction perpendicular to the axis of said hob spindle, work-holding means on said carriage, means for actuating the ,work-holding means to 'rotate the work relative to said hob including a forwardly extending shaft connected with said driven shaft, and means for reciprocating the carriages including a second forwardly extendin shaft also arranged to be driven from sai driven shaft.

18. Ina gear roughing machine, the combination of a base having an a erture in its upper side, a. carriage mounte on the base, a housing secured to the underside .of' the carriage and depending through said aper-, ture, a work-holding spindle mounted in the carriage, driving means for said spindle including an upright member having its upper end .in gearing connection with the spindle and having a worm wheel at its lower end, a driven shaft mounted in the base, and

a worm having a splined connection with said shaft and arranged t6 mesh with said worm wheel.

19. In a gear roughing machine, the combination of a hob, a carriage mounted for movement in a direction perpendicular to the axis of the hob, a work-holdin fixture mounted on the carriage and inci ilding a spindle adapted to clamp afpiece of work for engagement by said hob, said-fixture beingconstructed' to provide on the side of the fixture opposite the hob an opening through which access may be had to. the work.

20..A gear roughingmachine comprising, in combination, a base, a hob mounted on an axis extendin transversely of thebase substantiallymi way between its ends, worksupportin carriages at opposite ends of the base mova 1e to carr'y the work radially int:

at a relatively high speed.

and out of engagement with the hob, means 4 for reciprocating said carriages, and'means for controlling the last-mentioned means manually operable [to start the carriage to cause it to moveithe' work into engagement with the hob and'to'return itto an'inopera- .tive-position and automaticall operable to stop the carriage when in sue inoperative position.

21. In a gear roughing machine, the combination of a'hob, a carriage, means on said carriage for rotatably supporting the work, and means for moving the carriage to cause the work to move radially into and out of engagement with said hob, said means including a cam operable to move the carriage'initially at a relatively hi h speed until the. work is engaged b the ob, then ata slow or feeding speed, tlien holding the carriage stationary for a predetermined interval, and finally withdrawing the work- 22. A ge'ar-hobbing maehinehaving, incombination,'a hob, a carria e reciprocable toward and away from the ho in a direction perpendicular to the axis. of the hob aworkspindle on the carriage,'mechanisin or reci rocati'ng the carriage and for. rotating t e work spindle in timed relation to the hob,

a clutc controlling said mechanism and manually operable to start the carriage and the work spindle, and means for automatically operating said clutch to stop the carriage in inoperative positionand the work-i spindle upon the completion of one to and from reciprocation of the carriage.

In testimony whereof, I have hereunto aflixed my signature. k I

-, JOHN-EDGAR. 

